1. Field
Apparatuses and methods consistent with exemplary embodiments relate to an image display apparatus, and more particularly, to a transflective image display apparatus which can display images by transmitting or reflecting light and a control method thereof.
2. Description of the Related Art
Recently, liquid crystal display apparatuses have been widely used as image display apparatuses. Typical liquid crystal display apparatuses have an excellent image display capability, but use passive components that display images by using light emitted from a backlight unit instead of using active light emitting components.
FIG. 1 is a view schematically illustrating a structure of a typical liquid crystal display apparatus that displays images by using a backlight unit.
Referring to FIG. 1, a liquid crystal display apparatus 100 has a structure in which a first vertical linear polarizing plate 103, a liquid crystal display panel 102, and a second vertical linear polarizing plate 101 are stacked one after another on a backlight unit 104.
Non-polarized light W emitted from the backlight unit 104 changes to vertical linear polarized light while passing through the first vertical linear polarizing plate 103, and the vertical linear polarized light passes through the liquid crystal display panel 102. If a voltage is not applied to the liquid crystal display panel 102, as illustrated in FIG. 1, the vertical linear polarized light passes through the liquid crystal display panel 102 in the same state, and then also passes through the second vertical linear polarizing plate 101 with the same polarization direction in the same state so that a user will be able to see an image.
However, if the voltage is applied to the liquid crystal display panel 102, the vertical linear polarized light emitted from the first vertical linear polarizing plate 103 is changed to horizontal linear polarized light after passing through the liquid crystal display panel 102. The horizontal linear polarized light cannot pass through the second vertical linear polarizer 101 because the horizontal linear polarized light is not matched with the polarization direction of the second vertical linear polarizing plate 101. Accordingly, the liquid crystal display apparatus 100 does not display an image and looks dark to the user.
The transmissive liquid crystal display apparatus 100 using the backlight unit 104 always displays images by using the backlight unit 104 in which separate light sources are disposed. Therefore, there is a disadvantage that the liquid crystal display apparatus 100 has a large power consumption.
Accordingly, there is a need to develop a transflective liquid crystal display apparatus that can reduce power consumption by adaptively using a reflection mode and a transmission mode depending on the intensity of external light. When the external light is strong, as, for example, when a user is in bright sunlight, the transflective liquid crystal display apparatus uses the reflection mode in which it displays images by using the external light without using the backlight unit. When there is no external light, the liquid crystal display apparatus uses the transmission mode in which it displays images by using the backlight unit.